The present invention relates to apparatus for, and a method of, laying a pipe line composed of pipe sections arranged end-to-end.
In the construction of pipe lines it is known to excavate an open trench and to arrange pipe-sections end-to-end in the trench. One way of excavating the trench is to utilize an advanceable drive shield composed of elongate cutter planks displaceably supported by a frame or frames. The planks define and support the trench walls and are driven forwards individually or in groups to penetrate a working face at the front end of the trench.
The pipe sections can be lowered into the trench behind the shield and connected up end-to-end before the trench is refilled. In water logged ground the pipe laying operation becomes difficult and to overcome this difficulty it has been proposed to use a sealed receptacle into which the pipe sections can be lowered. This receptacle has an opening through which the previously-installed pipe section extends and the receptacle can be shifted up from time to time as the work progresses. Despite the general success of this form of apparatus there are still problems in certain areas, notably the shifting of the shield and the receptacle and general adjustment and control especially where the pipe sections are relatively large and heavy and/or where the soil is especially water laden.
A general object of the present invention is to provide an improved apparatus and method for the construction of the pipe lines.